Answer
In a fission reaction, the neutron-rich heavy nuclei decay to smaller daughter nuclei, which will emit neutrons to become more stable.
Work Step by Step
As seen in Figure 30-2, relatively lighter nuclei are stable with approximately equal numbers of protons and neutrons. However, heavier nuclei have a higher neutron to proton ratio, which mitigates Coulomb repulsion between the positively-charged protons.
